Fish oil supplements' omega-3 and omega-6 fatty acids may protect against various cancers, according to a study involving 253,000 UK Biobank participants. Higher omega-3 levels were linked to lower rates of colon, stomach, lung, and other digestive tract cancers, while high omega-6 levels reduced risks of 14 cancers, including brain and melanoma. However, high omega-3 levels slightly increased prostate cancer risk. The study, published in the International Journal of Cancer, suggests dietary focus on these fatty acids.